Process of preparing aconitate fumarate adducts



Patented Aug. 24, 1954 PROCESS OF PREPARING ACONITATE FUMARATE ADDUCTSJoachim Dazzi, Dayton, Ohio, assignor to Monsanto Chemical Company, St.Louis, Mo., a corporation of Delaware No Drawing. Application May 24,1951, Serial No. 228,113

2 Claims.

The present invention relates to organic compounds and deals moreparticularly with addition products of dialkyl fumarates and trialkylaconitates, to methods of preparing the same, and to vinyl chloridepolymers plasticized with the addition products.

According to the invention there are provided new and valuablepolycarboxylates in which one mole of a dialkyl fumarate in which eachalkyl radical has from 1 to 4 carbon atoms is combined with one mole ofa trialkyl aconitate in which each alkyl radical has from 1 to 4 carbonatoms. The new polycarboxylates are formed by a simple additionreaction, in which one mole of the fumarate adds to one mole of theaconitate. While the structure of the 1:1 adducts thus formed cannot bedefinitely determined, the adducts are believed to be penta-alkyl1-pentene 1,2,3,4,5-pentacarboxylates, the addition reaction proceedingprobably according to the scheme:

oH.ooY

HC-COOY c.0002" H .oooY'+R-ooo.oH OILOOOY mooooY" orrooorv 11.00012 inwhich Y, Y, Y", R and R are alkyl radicals of from 1 to 4 carbon atoms.

Dialkyl fumarates and trialkyl aconitates useful for the preparation ofthe present adducts are esters in which the alcohol portion of themolecule is derived from one alcohol, i. e., the diethyl, di-isopropyl,or di-n-butyl iumarates and the trimethyl, tri-n-propyl or triisobutylaconitates, or mixed esters such as ethyl methyl fumarate, propyldiethyl aconitate, butyl ethyl fumarate, etc.

The addition reaction is effected simply by heating the fumarate withthe aconitate at a temperature of at least 200 C. until formation of the1:1 adduct has occurred. The heating temperature may be from 200 C. to300 0., depending upon the nature of the individual reactants;

it should not exceed a temperature at which either reactant isdecomposed. Refluxing temperatures of the reaction mixture arepreferred. Termination of the reaction is generally evidenced by notingcessation in rise of the refluxing temperature. The course of thereaction may also be followed by noting the change in the refractiveindex of the reaction mixture.

Since the present products are formed by the addition of one mole of thefumarate to one mole of the aconitate molar equivalents of the reactantsmay be advantageously employed in the reaction mixture. However, sinceany unreacted materials may be readily recovered from the reactionproduct, an excess of either reactant may be used; and in order toassure complete reaction of the less readily available aconitates, it isgenerally preferred to use an excess of the dialkyl fumarate in theinitial reaction mixture. An excess of the fumarate also serves as adiluent for the reaction.

The present adducts are stable, high-boiling polycarboxylates whichrange from clear, viscous liquids to waxy solids. They areadvantageously used for a variety of industrial purposes, and arecharacterized by conferring improved plasticity to synthetic resins andplastics when incorporated therein. They impart increased flexibility tovinyl chloride polymers, which flexibility is retained at even lowtemperatures. At high temperatures, the present adducts are not readilyvolatilized from the plasticized composition, even when present inconcentrations of up to 50% by weight.

The invention is further illustrated, but not limited, by the followingexamples.

Example 1 A mixture consisting of 258.1 g. (1 mole) of triethylaconitate and 342.76 g. (2 moles) of diethyl fumarate was heated atrefluxing temperature (220 C.) for 3 hours and then for about 15 hoursat a temperature of from 201-190 C.

The drop in temperature indicated the presence Example 2 parts ofpolyvinyl chloride and 40 parts by weight of the adduct of Example 1were mixed on a rolling mill to a homogeneous blend. During the millingthere was observed substantially no fumes and discoloration. A moldedsheet of the mixture was clear, transparent and substantially colorless.Testing of the molded sheet by the Clash-Berg method gave a lowtemperature flexibility value of 3.0 C. Tests on the volatilitycharacteristics of the plasticized composition employing the methoddescribed by the American Society for Testing Materials under thedesignation D-744-44T gave a volatility value of 2.9 per cent. Whensubjected to a heat of 225 F. for a period of 30 minutes the clarity andcolor of the molded product were substantially unchanged.

While the above example shows only compositions in which the ratio ofplasticizer to polymer content is 40:60, this ratio being employed inorder to get comparable efiiciencies, the content of adduct to polyvinylchloride may be widely varied, depending upon the properties desired inthe final product. For many purposes a plasticizer content of, say, fromonly 10 per cent to 20 per cent is preferred. The present adducts arecompatible with polyvinyl chloride over wide ranges of concentrations,up to 50 per cent of esters based on the total Weight of the plasticizedcomposition yielding desirable products.

Although the invention has been described particularly with reference tothe use of the present adducts as plasticizers for polyvinyl chloride,they are advantageously employed also as plasticizers for copolymers ofvinyl chloride, for example, the copolymers of vinyl chloride with vinylacetate, vinylidene chloride, etc. Preferably, such copolymers have ahigh vinyl chloride content, i. e., a vinyl chloride content of at least'70 per cent by weight of vinyl chloride and up to 30 per cent by weightof the copolymerizable monomer.

The plasticized polyvinyl halide compositions of the present inventionhave good thermal stability; however, for many purposes it may beadvantageous to use known stabilizers in the plasticized compositions.Inasmuch as the present adducts are substantially unreactive with thecommercially available heat and light stabilizers which are commonlyemployed with polyvinyl chloride or copolymers thereof, the presence ofsuch materials in the plasticized materials does not impair the valuableproperties of the present esters. The present adducts are of generalutility in softening vinyl chloride polymers. They may be used as theonly plasticizing component in a compounded vinyl chloride polymer orthey may be used in conjunction with other plasticizers.

What I claim is:

l. The method which comprises heating at a temperature of at least 200C., a trialkyl aconitate in which each alkyl radical has from 1 to 4carbon atoms with a dialkyl fumarate in which each alkyl radical hasfrom 1 to 4 carbon atoms, and recovering from the resulting reactionproduct an adduct in which 1 mole of the said aconitate is combined with1 mole of said fumarate.

2. The method which comprises heating, at a temperature of at least 200"C., a mixture of triethyl aconitate and diethyl fumarate and recoveringfrom the resulting reaction product an adduct in which 1 mole of theaconitate is combined with 1 mole of the fumarate.

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date 2,472,135 Weizmann June 7, 1949 2,485,099 Karasch Oct. 18,1949 2,503,401 Mattano et al. Apr. 11, 1950 2,509,199 Moore May 30, 19502,517,351 Reid Aug. 1, 1950 2,526,395 Nichols Oct. 17, 1950 2,555,595Morris June 5, 1951

1. THE METHOD WHICH COMPRISES HEATING AT A TEMPERATURE OF AT LEAST 200*C., A TRIALKYL ACONITATE IN WHICH EACH ALKYL RADICAL HAS FROM 1 TO 4CARBON ATOMS WITH A DIALKYL FUMARATE IN WHICH EACH ALKYL RADICAL HASFROM 1 TO 4 CARBON ATOMS, AND RECOVERING FROM THE RESULTING REACTIONPRODUCT AND ADDUCT IN WHICH 1 MOLE OF THE SAID ACONITATE IS COMBINEDWITH 1 MOLE OF SAID FUMARATE.